Grace is haunted by an old case that she assisted on at the beginning of her career when she is asked to give evidence at the assailant's appeal hearing.

Someone possibly copying the past crimes begins harassing Grace about her testimony against Tony Greene. If she doesn't admit that she was wrong about him, the assailant promises to murder the victim he/she is holding hostage.

As DNA evidence from an old case of Spencer's (while he was working for the Atomic Energy Constabulary) is re-examined it appears that the wrong man was sent to jail. Someone tries to coverup the new evidence, causing all eyes to turn to Spencer.

As DNA evidence from an old case of Spencer's (while he was working for the Atomic Energy Constabulary) is re-examined it appears that the wrong man was sent to jail. Someone tries to coverup the new evidence, causing all eyes to turn to Spencer.

A criminal is about to be released, the team is sure he is a serial killer. They enter in a race against the clock to prove their suspicions and prevent his upcoming release.

A criminal is about to be released, the team is sure he is a serial killer. They enter in a race against the clock to prove their suspicions to prevent his upcoming release.

A millionaire businessman is found dead, a year after he dissapeared. It appears that during the time he was missing he was being held prisoner. But why...

The team discover the brutally murdered body of a man in the same cellar that the businessman was held hostage in. While investigating the two victims, the team find an unlikely suspect. They're positive of his connection to the murders, but need to collect the evidence to prove it.

Boyd is suspended from work after being involved in a hit and run accident while possibly under the influence. While also trying to find out who framed Boyd, the team continue trying to find out if Vine is innocent or not.

Under the impression that he may receive a confession, Boyd accepts the invite for a visit to the prison from former police officer Eddie Vine, who is serving a life sentence for murdering his friend and former fellow officer, Tom Pallisser.

Spencer goes undercover as a prison inmate to investigate the possible reasons for the murders from the man convicted of committing the crimes. To Spence's dismay, the man (who is too scared to say anything about what happened) commits suicide before he can be coerced into revealing who the real killer is.

A mummified body is discovered in a disused airliner that has been parked in the desert for 6 years. There are indications of a link to an armed robbery at Heathrow Airport six years earlier, and a murder at around the same time. Our team gains two new members. DS Andrea Stephenson takes over for DS Mel Silver, and the new mad scientist is Dr Felix Gibson.